Conventionally, various information recording and reproduction apparatus (hereinafter, simply referred to as an “information recording and reproduction apparatus”) such as a compatible player, which records and reproduce data on/from various optical disks such as a DVD (Digital Versatile Disk) and a CD (Compact Disk) having different standards, are provided. In the information recording and reproduction apparatus of this type, an increase in recording speed of data on an optical disks such as a DVD-R is desired to be increased in order to improve the convenience for a user and discriminate the apparatus from another product.
However, in an optical disk such as a DVD-R or a DVD-RW, a pigmentary change or a phase change occurs when a total amount of energy of an optical beam irradiated per predetermined unit time exceeds a predetermined threshold value, thereby recording various data. For this reason, when a relative speed of the optical disk to an optical beam the recording speed of which is increased, data recording cannot be realized without increasing the amount of energy of the irradiated optical beam.
On the other hand, as a light source used in the information recording and reproduction apparatus of this type, a light source in which an amount of heat radiation increases with an increase in outputtable wattage, i.e., at present, in terms of countermeasure against heat radiation, no more than 150 mW (milliwatt) is realized. For this reason, a theoretical maximum recording speed depends on the performance of the light source, and a recording speed cannot be desired to be further increased unless a new light source is developed.
Conventionally, the following proposal is made. That is, for example, two light sources corresponding to optical beams having wavelengths of 780 nm and 650 nm are simultaneously turned on in recording data on a CD-R, and a tracking error signal and a focus error signal are acquired by using the optical beam having the wavelength of 780 nm, so that the using efficiency of the optical beam having the wavelength of 650 nm used in data recording (see Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2000-173084